I agree with you on the protect the children 24x7. There are layers of protection you can do; however, once they are in public and away from you "game over".
Sure there is porn protection, limiters for time and what not, but that can't stop the child from taking a mobile device and hooking into an open wifi ... and boom.
Sexuality in American is hosed in the worst way. We have both men and women so thirst for companionship and intimacy it is creating edge case and deviant behavior (true not one where a christianity group calls it) as more of the norm, because if people had regular release and outlets, it would reduce the pressure and thirst.
I work in high tech where I have to help make some of the protection systems you are thinking about and the $$$ to do so would make you gag. People are concerned about climite change, well the amount of CPU/GPU horsepower required to scan every second of every video and picture would make you go ugh.
Band aids upon band aids. As for heirarchal rights (which ironically makes me think of Starship Troopers and the original author where that kind of setup existed), it is a slippery slope.
Public spaces should have decency laws and rules, but you can see people enforcing swear words for example and picture that madness. We saw what happened with Hollywood with it's decency laws around sex in the 1950s. What then happened was movies imported from Europe slid in and viola.
My view on some of it maybe jaded now because I am watching Handmaiden's Tale ...